Attachment insert



y 1945- w. M. KOHRING ATTACHMENT INSERT Filed June 23, 1943 INVENTOR. 1%

Patented May 21, 1946 ATTACHMENT INSERT Wilbur M. Kohring, Lakewood,Ohio, assignor to Continental Carbon, Inc., a corporation of OhioApplication J line 23, 1943, Serial No. 491,891

3 Claims.

My invention relates in general to an attachment insert and moreparticularly to an attachment insert adapted for anchoring a cable ormaking electrical contact with an electrical device such for example asan electrical resister.

An object of my invention is a. provision of an abutment contact insertwhich may be pressed into a recess and which cannot be readily removedor pulled out when once depressed in the recess.

Another object of my invention is the provision of an attachment inserthaving attachment means upon which a cable may be screwed or otherwisefastened, the attachment means bein connected to a cylindrical portionfor stabilizing or rigidly supporting the attachment means against sideplay or misalignment within the recess.

Another object of my invention is the provision of an attachment insertwhich has outwardly extending teeth that dig into the side wall of arecess, as the insert is pressed into the recess, the said teeth havingburr-like shaped points which oppose any force tending to remove theinsert from the recess.

Another object of my invention is the provision of an attachment insertarranged to be depressed in a stepped recess having a shoulder therein,the

attachment insert having a body which fits closely within the small boreof the stepped recess to give stability to the insert within the steppedrecess, the body having outwardly extending teeth to dig into the sidewall of the large bore of the recess as the insert is pressed into therecess, the pressing movement of the insert into the stepped recessbeing arrested upon the teeth engaging the said shoulder.

Other objects and a fuller understanding of my invention may be had byreferring to the following description and claims taken in conjunctionwith the accompanying drawing in which:

Figure 1 illustrates a cross-sectional view of an electrical resisterunit having attachment inserts for connecting cables thereto;

Figure 2 is a perspective view of the attachment insert embodying thefeatures of my inventlon:

Figure 3 is a perspective view of a resister element;

Figure 4 is a fragmentary view of my attachment insert and showsparticularly the outwardly extending teeth;

Figure 5 is across-sectional view taken'along the line 55 of Figure 4:and

Figure 6 is a view of a modified electrical device or resister unitembodying my attachment insert.

With reference to Figure 1, I illustrate two of my attachment inserts,which are indicated by reference character I2, as being embodied in aresister unit such for example as a cable type suppressor whichcomprises generally a hollow insulated tube I0 having a resister elementii disposed within the hollow tube l0. Each end f the resister elementII is arranged to be electrically connected to the electrical cables IS.The electrical connections between each end or the resister element iiand the electrical cables it are accomplished through my improved insertattachments [2 which constitute the subject matter of the presentinvention.

As shown in Figure 2, the attachment insert comprises a body 20 having ascrew attachment means 15 extending therefrom and being inte grallyconnected thereto. The screw attachment means l5 may be of any suitableconfiguration or form and is preferably of the conventional wood screwtype which screws into the central ortion of the cable I6. Asillustrated, the cable generally consists of flexible strands of softcopper wire covered with an insulation which comprises generally softrubber-like material. In attaching the cable to the screw attachment l5,it is only necessary to insert the end of the cable upon the point ofthe screw and screw the cable onto the screw while at the same timepressing the cable into the bore it within the hollow insulated tubeill. The rubber-like material of the cable as it is expanded by thescrew I5 makes a good water-proof, tight joint between the cable and thehollow insulating tube ill. The manner in which the cable is attached tothe screw i5 of my type of insert may be substantially the same as thatshown in United States Patent No. 1,909,248, patented May 16, 1933, inthe name of Glen F. Benkelman and assigned to the present assignee.

A great deal of difliculty has been experienced in attaching orconnecting the cables to the ends of a resister element in a hollowtube, and I have been able to solve this diiflculty by the use of myattachment. The anchoring means for holding the attachment insert withinthe hollow tube is accompanied by outwardly extending teeth 22. Theattachment insert is arranged to be pressed into a stepped recess havinga first bore ll into which the body 20 closely fits and a second bore l8into which the teeth engage. The body 0 which fits closely within thefirst bore i'l stabilizes the attachment insert within the steppedrecess.

The screw attachment l must the so rigidly mounted that it can withstanda considerable amount 01' sidepressure and under test must be able tostand the heavy side pressure from a screw driver which is used as alever against the side wall of the bore. l8 with the point of the screwdriver engaging the screw attachment IS, The teeth 22 havea slightlylarger diameter than the inside diameter of the second bore l8 so thatwhen the insert is pressed within the stepped recess, the teeth dig intothe side wall of the second bore, the pressing movement of the insertinto the recess being arrested when the teeth engage the shoulder 19between the first and second bores I! and i8.

As shown in Figure 5, the ends of the teeth have burr-like sharp pointswhich dig into the side wall of the second bore l8 and oppose any forcetending to remove the insert from the re-.

cess. such, for example, as tension being applied to the cable It. Inother words, as the attachment insert is pressed into the steppedrecess, the teeth scratch or plow longitudinal grooves of slight depthin the side wall of the second bore, and then when a reverse movement orpull is applied to the cables which would tend to remove the inserts,the sharp burr-like points dig fur-.- ther into the side wall and resistthe removal of the insert from the stepped recess. The combined actionof the teeth 22 together with the body 20 anchors and stabilizes theattachment insert l2 within the stepped recess so that the attachmentinsert cannot be misaigned therein and cannot be readily removedtherefrom.

The body 20 of the attachment insert is pro-, vided with a depressedportion 2| on the lefthand end of the unit as shown in Figure l. Thedepressed portion 2| is arranged to partly pocket a mass of tin foil l3for making a connection or contact between the attachment insert and theleft-hand end of the resister element II. The depressed portion 2| ofthe insert, located at the right-hand end of the resister II, isarranged to receive the end of a spring M which presses against the endof the resistor element H. The combination of the mass of tin foil l3and the spring 14 provides a good electrical connection between theresistor element H and the attachment inserts I2.

In Figure 6 I show a modified form of a suppressor, being generallyreferred to in the trade as a spark plug suppressor. In thisarrangement, the right end of the resistor element ll engages the spring14 which presses against a portion 26 of a hollow terminal 21 which isarranged to be connected to the distributor or other electrical part ofthe electrica1 ignition system. In Figure 6 only one of my attachmentinserts is used and is pressed into a stepped recess of the hollowinsulated tube 28 in the same manner as that described with reference toFigure 1.

In addition to being used for a cable attachment, my insert may be usedfor making any abutment contact whether for establishing electricalcontact with a current carrying element or formaking a good mechanicalengagement with an adjacent part.

Although I have described myinvention with a certain degree ofparticularity, it is understood that the present disclosure has beenmade only by way of example and that numerous changes in the details ofconstruction and the combination and arrangement of parts may beresorted scope of the invention as hereinafter claimed.

I claim as my invention: I a

1. An attachment insert adapted to be pressed into a stepped recesshaving a first bore portion defined by internal walls and a second boreportion defined by internal walls with a shoulder therebetween, saidfirst bore portion being smaller in diameter than the second boreportion, said insert comprising a body and cable attachment meansconnected to the body and extending therefrom, said body having astabilizing plug insert portion and an anchoring portion, saidstabilizing plug insert portion being adapted to closely interfit intothe first bore portion and stabilize the insert in the recess, byengaging the said internal walls thereof, said anchoring portion havingoutwardly extending teeth which dig into the said internal side wall ofthe second bore portion as the insert is pressed into the steppedrecess, the pressing movement of the insert into the stepped recessbeing arrested upon the teeth engaging the said shoulder, andinterlocking means 'on said teeth to engage the said side wall andoppose any force tending to remove the insert from the recess.

2. An attachment insert adapted to be pressed into a stepped recesshaving a first bore portion defined by internal walls and a second boreportion defined by internal walls with a shoulder therebetween, saidfirst bore portion being smaller in diameter than the second boreportion, said insert comprising a body and cable attachment meansconnected to the body and extending therefrom, said body having astabilizing plug insert portion and an anchoring portion, saidstabilizing plug insert portion being adapted to closely interfit intothe first bore portion and stabilize the insert in the recess, saidanchoring portion having outwardly extending teeth which dig into thesaid internal side wall of the second bore P rtion as the insert ispressed into the stepped recess, the pressing movement of the insertinto the stepped recess being arrested upon having burr-like sharppoints which oppose any force tending to remove the insert from therecess.

3. An attachment insert adapted to be pressed into a stepped recesshaving a first bore portion defined by internal walls and a second boreportion defined by internal walls with a shoulder therebetween, saidfirst bore portion being smaller in cross-sectional area than the secondbore portion, said insert comprising a body and cable attachment means,said body having a stabilizing plug insert portion adapted to interfitsnugly with the said first bore portion by engaging the said internalwalls thereof and stabilize the insert in the recess, and said bodyhaving an anchoring portion including means with burrs thereon, saidmeans and burrs thereon being adapted to di the insert from the recess.

WILBUR M. KOHRING.

